I received an email today asking me how to model a groin vault in Revit. In lieu of an email reply, I decided to record a quick video to show the basic steps. I started with a simple extrusion roof using a half-round arc. Then drew a second one at 90 degree. Next you use the join roof command on the Modify tab to connect them together. I tried using a dormer opening to cut the underside of the groin vault. I did not have much success in this attempt, but I think it had more to do with the fact that my geometry was perfectly flush at the bottom. I had the same issue with joining the roofs in the step above and so had to make the intersection barrel vault slightly shorter to get it to work. So perhaps if I also made it slightly above the Level 2 plane, it also would have worked with the dormer opening. Instead, I went with an in-place void form in the video. Finish it off with cut and join geometry.

It sometimes takes a little fiddling to get it to work. You might also want to try a Vertical Opening cut instead. Look at the roof in plan. Then select it. Click the Vertical Opening button on the ribbon. Sketch the shape of a 45 degree cut. You want to remove one end of the roof so that it is pointed when finished. This would give you one side of the four-sided vault. Then you can mirror and copy the result to make the vault. This will give a nicer result than what I showed in the video actually.

Just want to push one step forward. At the moment, I’m modeling a historical church with a Groin Vault system made of plaster and timber frame. For the accurate documentation, it’s really important for me to model the wood structure of the roof. Is there a method that you will recommend for modeling timer elements on a curved surface? I tried the timber frame plugin. However, the software doesn’t support the groin vault roof.

This sounds like a fun project. If the cross section profile of the vaults is a circle or ellipse, it should be pretty easy to create the beams. They would have to be custom families. If the shape is more complex, it might be trickier. You can of course try the massing environment and adaptive components. Or possibly even Dynamo. I’d love to discuss the project with you. Send me an email using the contact form here on my site if you’d like to discuss it. Thanks.